Which Oil (also filter and 'wet clutch' question)?

I know it's a bit like which toothpaste or which bread but I need advice about oil for the ZXR750J. Value for money is good, protection (obviously) and easily available. It's just a weekend warrior toy for fun in the twisties, I'm not revving the ring out of it. Will probably change every 4000km or so.

Also does anyone have a Ryco part number for the oil filter? I've checked the website but it must only look up cars it keeps thinking I mean Kia .

Also Is it good or bad to use that Nulon Oil System Flush stuff on bikes? I used to use it on the rally car to clean out the system before putting pretty new oil in.

Is the clutch a 'wet clutch' in this bike, and if so is it 'wet' by the engine oil? I don't know that much about bike clutches, but I've heard the term 'wet clutch' around, surely oil anywhere near the clutch plate faces would make it slip?

Maybe there's a couple of different topics here but I've stuck it all in the title, who can help?

I use Valvoline Premium XLD at $18 for 5 litres. Have used it for 60,000+ km with no problems.

It already exceeds Kwaka's manual recommendation anyway (SJ from memory).

Yes you are right, your clutch is soaking in your engine oil, dont ask me how it works, it just does

I know it's a bit like which toothpaste or which bread but I need advice about oil for the ZXR750J. Value for money is good, protection (obviously) and easily available. It's just a weekend warrior toy for fun in the twisties, I'm not revving the ring out of it. Will probably change every 4000km or so.

Also does anyone have a Ryco part number for the oil filter? I've checked the website but it must only look up cars it keeps thinking I mean Kia .

Also Is it good or bad to use that Nulon Oil System Flush stuff on bikes? I used to use it on the rally car to clean out the system before putting pretty new oil in.

Is the clutch a 'wet clutch' in this bike, and if so is it 'wet' by the engine oil? I don't know that much about bike clutches, but I've heard the term 'wet clutch' around, surely oil anywhere near the clutch plate faces would make it slip?

Maybe there's a couple of different topics here but I've stuck it all in the title, who can help?

As far as oil goes, I am really of the belief that the full synthetics are really beneficial for a HP or maybe two in racing and the ability to go longer in between changes. I believe if you use a good quality Dino (Read non-Synthetic) oil of the specific grade recommended and change it every 5k you can't go wrong.

In my race bike I use a 0W-5, and in the beemer I use a 20/50 and in the 9 a 5 or 10W-40.

As for the clutch, in a bike with a dry clutch, the clutch plate or plates are external to the oil supply or, outside the engine cases. In the case of the ZXR750J and most other Jap bikes, the clutch is bathed in the engine oil! Both have advantages and disadvantages. The beemer clutch is a single plate dry clutch and it's nice, the 9 is a multi plate wet clutch and is fine too!

With oil and wet clutches, the doctrine is that you don't use friction modified oils like car oils as it has adverse effects on wet clutches apparently although I have heard some argue the toss.

It looks like my options for the oil filter are K&N or Kawasaki, is there much difference really?

I like Penrite oil, not just 'cos it's decent oil, but I can get it a little cheaper.

HPR Gas 10 is what they recommend for bikes. It's a 10/50 semi-synthetic.

I used to use Motul 5100. Good oil, but pricey.

Strika's right, too. If the oil's changed regularly (religiously), all you have to do is meet or exceed the manufacturer's specced oil and (possibly) avoid friction modified oils.

Energy saving (low friction) oils are the ones that will cause clutch slip. The 10W-40 and thicker usually/always? are OK.
I use Shell Rimula Super 15W-40, a commercial diesel oil. It is a proven oil, not because of a motorcyle icon on the pack and race sponsorship, but through used oil analyses. If you want to research it yourself, it's called Shell Rimula in the US.

Energy saving (low friction) oils are the ones that will cause clutch slip. The 10W-40 and thicker usually/always? are OK.
I use Shell Rimula Super 15W-40, a commercial diesel oil. It is a proven oil, not because of a motorcyle icon on the pack and race sponsorship, but through used oil analyses. If you want to research it yourself, it's called Shell Rimula in the US.

I disagree with the bit about low viscosity oils causing clutch clip. I bought Bayliss' old ZX6R racer start of 1996. It had the original clutch plates from the factory in it still. It had run 0W-5 oil all it's life. I continued to run 0W-5 in it throughout 1996 and 1997 without any clutch slip. I then sold it to a mate who did the same, then he sold it to another guy who did the same. It's had 6 or 7 seasons of racing, using 0W-5 oil and NO clutch wear issues or slippage. I reckon that's either a bullet proof Kawasaki clutch or that low viscosity oils don't make clutches slip.

On road bikes, my ZX9 has done at least 40,000 klms with a low viscosity oil (0W-5 oddly enough) and has never clutch slipped. It's wheelspun making me think the clutch is slipping, but never slipped!

Most workshops stock Hiflofiltro oil filters as an alternative to OEM. You need a HF303.

I disagree with the bit about low viscosity oils causing clutch clip.

I'm not saying that all low viscosity oils cause clutch slip, but that is where the "car oils cause slip" misinformation comes from. When I say energy saving, I don't mean low viscosity, I mean the oils that actually say "energy saving". They also happen to be low viscosity.
I'm coming from the other direction saying that you're definitely safe if you don't use thin car oils.
PS For some reason it seems really cool that you have an ex race bike.

I disagree with the bit about low viscosity oils causing clutch clip.

I'm not saying that all low viscosity oils cause clutch slip, but that is where the "car oils cause slip" misinformation comes from. When I say energy saving, I don't mean low viscosity, I mean the oils that actually say "energy saving". They also happen to be low viscosity.
I'm coming from the other direction saying that you're definitely safe if you don't use thin car oils.
PS For some reason it seems really cool that you have an ex race bike.

It's pretty cool having a race bike too MiG! Oh, and it's not an Ex race bike as it still races, all be it sporadically!!